1. Field of the Invention
The present invention relates generally to the field of the hair manipulation products and systems, and particularly to a process and series of compounds that permanently straighten and/or curl hair.
2. Description of the Prior Art
The art of curling hair dates back as far as ancient Egypt, when the “mud method” was used. Wooden sticks used in the “mud method” were later replaced by metal rods, and as time progressed the rods were heated during the process. This use of heating rods was the foundation for the use of curling tongs that were still popular in the 1930s. The first permanent waving method introduced into the United States originated in France in 1884. This method included the use of concentrated seawater and heat.
All previous methods were abandoned when Charles Nessler devised a process for softening the hair using borax in 1906. Evans and McDonough introduced a method using mercaptans, first as depilatories and as cold-waving agents. The substituted mercaptans were found preferable in curling the hair because they are more efficient and have a less objectionable odor.
Various modifications to the use of the mercaptans products have been developed to improve the curling power and to reduce the damage done to the hair during the curling process. The most popular waving preparations have an alkaline pH in the range of 8.0 to 9.0. Acid waves, using derivatives of thioglycolic acid are simple amide salts and esters. Amides and esters of thioglycolic acid are potential sensitizers. These products are of little commercial importance due to their instability and irritation potential. Sulfite containing products can be used in tepid waving and found use in hair straightening in the presence of large amounts of urea and isopropyl alcohol.
Tepid waving, a form of heat waving has been used to increase reaction time between sulfites and hair. The temperatures used are moderate and well tolerated by consumers under a hair dryer. Steam flat irons and dry flat irons are used to straighten hair. When the tepid method is used the strength of conventional heat waving preparation is increased, while it is decreased in the cold wave products. Temperatures in the range of 20° C. to as high as 80° C. have been used in these procedures.
The physical process of permanently waving or straightening hair is caused by a change in the molecular configuration of the keratin molecule, giving the hair a lasting curl that cannot be changed by physical means. This change in configuration can be accomplished by the use of high temperatures, or by chemicals such as alkalis and certain sulfur compounds adjusted to a proper pH, in bases having a dissociation constant of less than 5×10−3.5. Water curls and temporary sets differ from permanent waves in that the curls are formed when unstable cross linkages are present, and tend to return to their normal configuration when moistened. The hair in its normal state is made up of regularly folded polypeptide chains with cystine, hydrogen and polar or salt linkages.
In order to permanently curl or straighten the hair, one must break the disulfide bonds. Before the chemical can break these disulfide bonds it must penetrate the cuticle of the hair. Both permanent waving of the hair and straightening of the hair have been popular ways of modifying hairstyles. People with unmanageable tight curly hair frequently have their hair straightened. Straightening the hair has been accomplished by using highly viscous alkaline preparations; the high viscosity helps to keep the preparation off the scalp. The most popular preparations are formulated with sodium hydroxide or potassium hydroxide. The pHs of these preparations range from eight to twelve.
All prior art products either permanently straighten or curl the hair using ingredients that are irritating to the skin. Consequently, manufacturers caution people who use these products to use protective gloves to apply the creams or solutions to the hair. They recommend protecting the skin of the person receiving the straightening or curling service as much as possible.
In general the alkaline products are left on the hair for a specified length of time. A test curl is taken to determine if the time of contact is sufficient to produce a satisfactory curl. When straightening the hair, the product is placed on the hair and stretched using a styling tool or brush. Large curlers are used to obtain wavy hair. In both curling and straightening processes, there is a second step required to reform the disulfide bonds in the hair. This is necessary to make reconfiguration permanent.
The shortcomings in the prior art are many fold. The primary drawback is the potential damage to the skin of the person receiving the treatment based on the high pH of the solutions used. Additionally, the processes provide a noxious smell that takes days or weeks to leave the hair. Also, universally, the hair is left in a damaged state and weaker than prior to the treatment. Accordingly, when the treated hair grows out, in order to maintain the curl or straightened state of the hair, only the newly grown hair can be treated without further damaging the hair. Another drawback to prior art methods is that the hair cannot be shampooed for several days after the procedure because the achieved result will be negated by shampooing in the days following.
It is the object of the present invention to overcome all of the drawbacks of the prior art by providing a composition of products and a process for use thereof that achieves the desired ends without any of the stated drawbacks.
It is an object of the invention to provide a product and process for straightening or curling hair that does not damage the skin of the person receiving the treatment based on the high pH of the solutions used.
It is an object of the invention to provide a product and process for straightening or curling hair that does not leave a noxious smell in the hair of the person.
It is an object of the invention to provide a product and process for straightening or curling hair that does not leave the hair in a damaged state and that actually may leave the hair in better shape than prior to the treatment.
It is an object of the invention to provide a product and process for straightening or curling hair that does not incur damage with multiple treatments.
It is an object of the invention to provide a product and process for straightening or curling hair that does not become undermined by the immediate shampooing of the hair after treatment.